ProAxsis: Advancing respiratory patient care
ProAxsis was founded in 2013 as a medical diagnostics spin-out of Queen’s University Belfast in Northern Ireland. ProAxsis has developed proprietary molecules, called Protease-Tags, which selectively bind active proteases and can be used in a range of diagnostic and disease monitoring tools. The company produces a commercially available immunoassay for research use and is currently developing a PoC test called NEATstik for routine monitoring of neutrophil elastase. Neutrophil elastase is involved in chronic respiratory diseases such as CF and COPD and is an established biomarker of infection and inflammation. Significant progress with the development of NEATstik was made in 2015 and, contingent on raising further funds in 2016, the company expects to be ready for EU commercialisation by mid-2017.
Active proteases (‘molecular scissors’) play a key role in many physiological processes and are considered important therapeutic targets, as well as being biomarkers of many diseases. They may be unregulated in diseases including cancer, heart disease, stroke, Alzheimer’s disease, rheumatoid arthritis, multiple sclerosis, CF and COPD. Current assay systems for proteases utilise chromogenic or fluorogenic substrates, are often complex and may not be sufficiently specific to detect the active form of the enzyme. ProAxsis has developed novel and patented Protease-Tags to irreversibly inhibit/trap active proteases. Because they are designed to form a bridge to a solid support via covalent binding, they can be combined with established diagnostic technology platforms such as ELISA, lateral flow or multi-analyte biochips.
ProAxsis’s first Protease-Tag immunoassay kit was launched in August 2015 and is commercially available for research-only use, including academic labs and clinical research organisations involved in clinical trials. The kit measures active neutrophil elastase (NE), which is produced by white blood cells (neutrophils) in response to lung infections and is also a potential therapeutic target. Elastase destroys the elastic connective tissue that keeps the lungs supple, which results in permanent scarring. Clinical studies have shown that high neutrophil elastase levels are linked to deteriorating lung function (eg Sagel et al 2012). Sales in 2015 were modest, although the company expects them to grow as further pharma company customers are secured (following completion of internal validation testing). Beyond the NE kit, three further specific immunoassays are in development against different proteases targets, including those involved in pulmonary fibrosis, CF/COPD and acute respiratory distress syndrome.
ProAxsis is also developing a lateral flow device (NEATstik, Neutrophil Elastase Airways Test) for rapid, easy monitoring of NE levels in the clinic or home from sputum samples. It aims to be the first-to-market, PoC NE test. NE activity in respiratory diseases is responsible for significant airway damage and is a strong predictor of lung function decline. The goal is to detect increased NE levels earlier to reduce exacerbations and hospitalisation risk in patients with CF and COPD, and improve health outcomes.
The chronic respiratory diseases CF and COPD are associated with frequent lung infections, irreversible tissue damage and lung function decline. There are 70,000 patients diagnosed with CF worldwide (30,000 patients in the US and Canada and c 40,000 elsewhere, mainly in Northern Europe) and 35.7 million patients with COPD in the US and EU. The treatment of lung diseases is estimated to cost the UK NHS £4.7bn a year and, according to NICE, “a reduction of 5% in COPD exacerbations would be expected to save the NHS £16 million per annum”.
The target population for home testing is adult CF patients and moderate-severe COPD patients, 65% and 25% of whom respectively are ‘natural sputum producers’. Even at a conservative price ($25 in the US, £15 in Europe), assuming a 40% share of CF patients (testing weekly) and a 20% share of COPD patients (testing monthly), ProAxsis estimates the European CF/COPD home test market could be around £16.5m. The US market would probably be twice this, giving an estimated US/EU market of c $70m, and these estimates are largely within line with our own. It should be noted that the test is still in the early stages of preclinical development and a marketable end user product has not been developed yet. However, we expect this process to be streamlined because the test utilises established technology and we predict R&D costs in the range of £3m. We expect the company to pursue CE marking in Europe and a 510(k) submission in the US, which would additionally limit R&D spending. In total we expect the company to need £4m in additional financing before profitability in 2020. It has announced that it will be seeking up to £7m in a Series A in H216.